This R01 project, "Step Ahead - - Activity and Diet Steps by Hospital Employees to Promote Health", will refine, implement, evaluate and disseminate an environmental worksite intervention to promote active living and prudent dietary patterns to reduce burden of overweight and obesity among employees. Worksites are opportune intervention settings, as most American adults spend significant amounts of time at work. The trial will be implemented at six hospitals affiliated with UMass Memorial Health Care in central Massachusetts. Hospitals are important worksite environments that employ large numbers of people in diverse job categories from diverse educational and socioeconomic backgrounds. Guided by an ecological framework, the intervention consists of multiple components that target the leadership, policy/procedural, social and physical environments at the organization and work unit levels, reinforced by social marketing and structured educational strategies. The intervention promotes active living, in which physical activity is incorporated into daily routine, and prudent diet, characterized by higher intakes of fruits and vegetables, fish, poultry, legumes and whole grains, lower intakes of high fat foods and refined grains and reduction of total caloric intake through reduced portion sizes. The intervention recognizes the importance of using the worksite as a setting to teach and practice these lifestyle changes in order to apply them to other areas of life. The study design is a randomized controlled trial, where the unit of randomization is the worksite, occurring within matched pairs, and the primary unit of analysis is the individual employee. A random sample (n=540) of employees, with an over-sample of African Americans and Hispanics will be selected to complete the evaluation component of the project. Measurement, which consists of physical assessments of body fat distribution and self-administered surveys, will be completed at 4 time points: 2 baseline and 2 follow-up, occurring at 12 month intervals. Primary endpoints are changes in body composition, measured by body mass index and waist-to-hip ratio. A comprehensive process evaluation will monitor intervention implementation. The project will be conducted in 2 phases. During Phase I, a leadership and employee participation plan will build interest and support and allow refinement of intervention strategies and methods. Intervention implementation and evaluation will occur during Phase II. A dissemination plan will then be implemented in collaboration with NHLBI and other funded projects.